Why doesn't the filling fall out of a sandwich?

Think of a sandwich in your hands. Feel the soft bread under your fingers. Inside, there might be cheese, or jam, or a slice of tomato. Maybe it is your very favourite kind.

You lift it up and take a big bite. The filling stays inside, snug between the slices. Not one bit drops onto your lap. So why doesn't the filling fall out of your sandwich?

The bottom slice sits under the filling. It holds the filling up, just like a little plate. So the filling has something to rest on. Without it, the filling would fall right through your fingers.

The top slice lies on the filling like a soft blanket. It presses down on it from above. Now the filling is tucked between two slices. Soft bread below, soft bread above, and the filling in the middle.

When you pick up your sandwich, your fingers squeeze it. Your squeeze pushes the two slices toward each other. The slices press the filling between them. What do you think the pressed bread and filling do to each other?

They grip, which means they hold on to each other so nothing slides. Bread has tiny bumps and holes all over. The filling presses into them and catches there. Cheese, ham and jam all catch on the bread this way.

The filling is heavy, and its weight pulls it down toward the floor. But the grip is stronger than that pull. That grip keeps the filling snug inside your sandwich. So the filling stays put, bite after bite.

One word to remember: grip. Your fingers squeeze the bread, so the filling grips it and cannot slide out.

Enjoy every snug, tasty bite of your next sandwich, little one.